I just called my sister who was doing about a month of Cardizem (diltiazem) (360 or 320 mg)...she just went to the doctor and told her to shove them where the sun don't shine. Her complaints were NO SLEEP, amphetamine(speed)-like fidgiting, chest pain, nervousness, depression, and rage spells.
(Sounds like my reactions to Norvasc- also a channel blocker).

Anyhoo, she was switched to Calan (Verapamil...anothe CCB) which she likes a lot...but it's only been a week.